Hey guys here a quick rundown . The new mini lathe come in and got it setup up ,checked out, It's SWEET. So i grab up a SR liner chucked it up and when to work,it's taking a little longer then i thought to cut but worth it. Finished to with 220 cross hone finishes. I mod my honer for the liners.. Ok enough talk here's acouple pictures. Still have few more thing to do, may have running motor to breakin by the weekend if my life doesn't get in the way.

now will that liner be as durable now? I am probably wrong, but I thought stock liners were coated in something that helped to harden the liner and protect against corrosion.

Randy!!! I am the liquor

GootyS I set the liner to the same spec as ST motor. The Piston is 27.57mm and the bore is 27.70mm which works out to .06mm clearance per side. Both the ST and SR have the same O.D.
I'm going to break-in the motor with no port mods and see how it performs then I will do some porting and check performance again. I know there will be guys out there wanting dyno reads well if someone has one i can borrow I'll love to use it.LOL I understand there only about 5 grand . I guess i could setup a engine stand and use props to see how much more prop it could pull over stock and figure power incease in percents but I'm sure that will not be good enough for some. First I'm going to see how it runs and performs holds up.

CoronaL , If there's a coating thats news to me. I have honed many liners on rebuilds that like look new today.

ok cool keep us up to date

Randy!!! I am the liquor

lronhide going to watch vibs if this goes as hope the next plan is SK720 for 700. was also thinking i'm going to weight both pistons and then again the ST after i clearance it for crank just to know the changes in the motor.

Awesome!! i shall wait for your feed back :-)

here's a few more picturs. Shoved off the top of liner to get 12:1 with SR shim but with ST shim it's 12.5:1 , tHe stock SR is 13:1 . I can remove .004 from liner but that's it , will wait and see how she runs on rotor rage 30% . Still waiting on UPS man for new crank and Rear bearing. If you look close you can see the light between the head and Crankcase. it's .010.. this area is normally about .035 clearnace...

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more...more...more..lol you saying the stock compression is 13:1 on the SR and with shaving some off the sleeve you getting 12:1? How much more can you go to get back to the 13:1 ratio or are you trying different compressions first?...or have a i lost the plot? :-)

Ok right now it is 12:1 with .2mm stock SR shim. Can change shim to ST .1mm shim yeilds 12.5:1 CR. Now i can still remove .1mm or .004 from top of liner and that along with .1mm shim get 13:1CR . Plan to work my way up on compression..

LighteningRC Yes it's YS91SR with ST piston liner has been bore/honed to 27.70mm from 27mm with long stroke SR yeilds 95.6..

Heliporz has got to be the slowest shipping around order crank on 5/31/10 still not here... not the first time on slow shipping.

using ST piston in SR motor the piston is to lower at TDC causing to low of compression ratio. so i cut some from top of liner this rasied CR. I want to see how it runs at 12 for 15%, 12.5 for 20% and 13 for 30% . im mainly interested in tuning at 12.5 and 13 also smoothness of motor. using SR liner because it is longer means longer intake runners than using ST liner. equals more torque/HP. From what i figure SR stock CR is 13:1 but i want try 12.5cr as 13 may cause rough or bad idle . I wont know till its running hopevully that will be this weekend.

Let us know how she goes

Man I just got my parts in But the ST shim is .020 or .008mm thick. Now i got to figure out where to get the .004mm or .010 shim that was in the ST motor i sold..... I need this to get 13:1 CR , if someone knows please inlighten me....Was going to start with 12.5:1 CR with .1mm shim and later shave .004mm more off liner to get 13:1 CR.. Guess i can email YS see what they tell me ... I'm Bummed

Looks like OS91HZ has .1mm shim and is 27.70 bore we may have a winner , Now i just need one in hand.... man this is getting to be like work.